active galactic nucleus

At the center of nearly every large galaxy sits a supermassive black hole. It doesn't just devour infalling gas; it also blasts some of it back out in powerful jets. These jets act like giant pistons, shoving the surrounding gas and heating it. Astronomers have long suspected that this is how black holes keep galaxies from cooling into cold star factories.

A particle with an energy of $$10^{18}$$ eV hitting Earth's atmosphere is like a tennis ball traveling at 200 km/h slamming into a wall. Astrophysicists have debated for decades where such projectiles come from. Gamma-ray bursts, brief and powerful explosions of gamma radiation, have long been suspected as accelerators.

Deep inside a neutron star, where matter is compressed to the density of an atomic nucleus, neutrons form a superfluid and protons form a superconductor. A neutron vortex is a quantized vortex in the superfluid, akin to a miniature whirlpool that cannot stop spinning.

Galaxy Mrk 590 behaves like a radio receiver that sometimes picks up a signal and sometimes fades into static. Its supermassive black hole has been brightening and dimming for decades, and astronomers caught every such 'switch-on.' In 2017, the receiver came alive again, but the VLA radio telescope heard not the signal they expected.

At the center of an ultra-compact dwarf galaxy, a very dense stellar system spanning tens of light-years, there is a vacuum cleaner at work. But instead of dust, it sucks in gas shed by dying stars. This gas does not fly off in all directions; instead, it spirals into a funnel, a rotating disk that gradually settles onto the black hole.

At the center of the Milky Way, where the supermassive black hole Sagittarius A* churns gas clouds like a millstone, astronomers have caught an irregular pulse. Gamma-ray emission, the most energetic light in the universe, arrives not as a smooth wave but with a break, as if the Galaxy's heart beats with arrhythmia.

The night sky in neutrino light resembles a canvas worked on by two hands. One holds a broad, soft brush: these are supernova remnants, the shells left behind after stellar explosions. The other grips a fine, hard pen — microquasars, binary systems where a black hole twists matter into narrow jets.

The XMM-Newton X-ray telescope stared at galaxy Mrk 1044 for two straight hours. Inside it, a black hole is surrounded by a swirling disk of superheated gas. This gas glows in X-rays, and its light flickers — brighter, then dimmer. For the first half hour, the flickering of soft and hard X-rays was in step.

At the heart of nearly every large galaxy sits a supermassive black hole. Usually it behaves quietly, but sometimes, like a waking volcano, it spits out narrow plasma jets. These jets glow in the radio band, making the galaxy 'radio-loud.' Astronomers have long known this happens, but they couldn't catch the very moment of switching on.

At the heart of nearly every large galaxy sits a supermassive black hole. Usually it behaves quietly, but sometimes, like a waking volcano, it spits out narrow plasma jets. These jets glow in the radio band, making the galaxy 'radio-loud.' Astronomers have long known this happens, but they couldn't catch the very moment of switching on.

In the southern sky, behind a dense veil of dust, hides a source of gamma rays — the most energetic light in the Universe. It shines so brightly that it can be seen even through this veil, but the object itself remains invisible. Astronomers pointed the ALMA radio telescope at the neighboring gas clouds and saw a pattern that gave the invisible object away.

A black hole with a mass of 35,000 Suns drifts through a galaxy's gas like a barge through fog. Its gravity rakes the material ahead of it, leaving a dense trail behind — a wake of gas. Some of that gas gets pulled into the black hole, and it grows.

The explosion of a massive star is not just a flash: it's a blow to the surrounding gas. But until now, no one had looked at how the gas itself moves at the sites of such explosions. Now astronomers have gathered data on 33 nearby supernovae and for the first time measured the turbulence of the cold molecular gas around them.

In the heart of the Perseus galaxy cluster lives the galaxy NGC 1275. From its core blows a wind of superheated gas — astronomers have now seen it in detail for the first time. The wind shows up in the glow of hydrogen and oxygen. It accelerates to 570 kilometers per second — faster than a bullet.

The cosmic detective story began with a quiet flash in the optical band. AT2019wzc slowly brightened and faded like a smoldering ember. But hidden inside was something more energetic — repeating soft X-ray bursts that astronomers call quasi-periodic eruptions. These eruptions last minutes to hours and repeat every few hours or days.

In the distant Cigar Galaxy, there is an unusual beacon. It doesn't shine in the usual sense: its rays are born in a scorching cloud around a black hole that is devouring matter from a companion star. Such objects are called ultraluminous X-ray sources. Their X-ray brilliance is so intense that it outshines entire galaxies. This cloud, the corona, is like a boiling cauldron.

In the distant Cigar Galaxy, there is an unusual beacon. It doesn't shine in the usual sense: its rays are born in a scorching cloud around a black hole that is devouring matter from a companion star. Such objects are called ultraluminous X-ray sources. Their X-ray brilliance is so intense that it outshines entire galaxies. This cloud, the corona, is like a boiling cauldron.

A black hole is not an absolutely black bag. In 1974, Stephen Hawking showed that it glows — faintly, but continuously. This radiation is born not inside, but outside, right at the boundary from which even light cannot escape. A new study sharpens the picture.

A globular cluster, a dense swarm of hundreds of thousands of stars, plows through a galaxy like a bullet through water. In ordinary dark matter (the invisible mass that holds galaxies together), it should quickly lose speed due to dynamical friction.

Deep inside molecular clouds hide natural amplifiers — cosmic masers. They work like lasers but in the radio band: excited molecules collectively emit waves of a single frequency, creating a bright beam. The catch is that these molecules often have several ways to shed energy.

At the centers of many galaxies lurk giant black holes. They are surrounded by dense clouds of hot plasma that emit a powerful X-ray glow.

At the centers of many galaxies lurk giant black holes. They are surrounded by dense clouds of hot plasma that emit a powerful X-ray glow.

A bright lantern in thick fog seems dim, while a weak flame in clear air can be seen a kilometer away. A similar oddity baffled astrophysicists almost half a century ago.

A marathon lasting 13 billion years started with different weights. A hundred solar masses — lighter than some gas clouds. A hundred thousand — gravitational dominance, comparable to an elephant among kittens. That's what black hole seeds looked like, ones that by our time should have turned into supermassive giants.

A gas disk with a mass of four hundred thousand suns encircles the black hole at the center of the Milky Way. Its gravity works like a gravitational rudder: slowly but inexorably turning the orbits of binary stars, driving them into the region where tidal forces tear the pair apart.

295 000 meters per second. Not even particles in solar coronal ejecta move that fast. But at the center of the galaxy cluster H1821+643, hot gas does exactly that. The quasar at its heart takes a breath, and its breath stirs everything around for 60 thousand light-years.

In the deep field of JWST, among thousands of galaxies, astronomers zoomed in on the source JADES-GS 209777 – and saw a cosmic chick. Its "shell" is a thick cocoon of gas and cosmic dust that long hid the growing black hole at its center. But at a redshift of 3,711 (1,8 billion years after the Big Bang), the shell began to crack.

The fastest wind in the Universe travels at 0,58 times the speed of light. It covers the distance from Earth to the Moon in two seconds. This wind is not a jet stream but a broad flow of gas erupting from the center of a galaxy. Not all black holes work the same: some create such hurricanes, while others produce narrow plasma beams.

Eight hundred million years after the Big Bang, and at the heart of a young galaxy a monstrous engine is already throbbing. A black hole with a mass of ten billion suns devours matter so greedily that its radiation should outshine everything around it. But outside, silence.

A branch falls into a whirlpool. It gets spun and broken, but sometimes a powerful fountain of water bursts from the center. Similarly, a black hole tears apart a passing star, and occasionally a blinding plasma jet, a jet, shoots into space.

In the early universe, just a few hundred million years after the Big Bang, astronomers see strange objects — little red dots. They are compact, red, and in their spectra, broad Balmer lines scream the presence of supermassive black holes. But how did the hole manage to accumulate millions of solar masses in such a short time?

A billiard ball clicks against another in complete darkness. The sound of the impact and the clatter of balls dropping into pockets: that's all you hear. This is roughly how physicists study the interactions of elementary particles at energies that no terrestrial accelerator can reproduce.

In April 2021, the antennas of the Event Horizon Telescope (EHT)—a global network of millimeter-wave radio telescopes — zeroed in on a tiny spot in the constellation Virgo.

At the heart of the giant galaxy Hydra-A, there's a hive of activity. A supermassive black hole shoots out two powerful plasma jets. They punch through the surrounding cloud of hot gas and inflate giant bubbles within it.

Dark matter is invisible to telescopes, but its gravity was revealed half a century ago by Vera Rubin. Since then, physicists have explored dozens of hypotheses, and one of the most elegant is primordial black holes, formed in the first moments after the Big Bang.

Deep inside a neutron star, matter is squeezed so tightly that familiar protons and neutrons give way to new players. Hyperons are born there — particles that harbor a strange quark.

At the center of many galaxies lurks an invisible cloud — a halo of dark matter. If this matter is cold and light enough, it behaves like a superfluid: it flows without friction, and any rotation in it twists into tiny quantum vortices — threads the size of an atomic nucleus.

The universe rewrites its history again and again. Where ordinary astronomy sees only a point, a black hole, gravitational waves peel back thin layers of the past, like an ancient palimpsest. The idea that black holes can grow by devouring each other, and their offspring can enter new unions, has been discussed by astrophysicists for half a century.

The invisible hand of dark matter squeezes galaxies in gravity's embrace, yet its nature has remained elusive for nearly a century.

The cosmic spectacle unfolds on the stage of Galaxy галактики Centaurus A. In the lead role: a supermassive сверхмассивная чёрная дыра with a powerful jet that pierces space for hundreds of thousands of light-years.